1. Field of the Invention
The present invention relates to an organic light emitting display and method of fabricating the same and, more particularly, to an organic light emitting display including an inorganic pixel defining layer formed using a deposition method and method of fabricating the same.
2. Description of the Related Art
An organic light emitting display (OLED) among flat panel displays is an emissive display of electrically exciting organic compound to emit light so that it does not require a backlight unit, unlike LCD. Therefore, the OLED may be fabricated in a lightweight and thin type and by simple processes. In addition, since the OLED may be fabricated at a low temperature and has characteristics of a fast response speed less than 1 ms, low power consumption, a wide viewing angle due to the emissive display, and high contrast, the OLED is attracting public attention as a next generation flat panel display.
Generally, the OLED includes an organic emission layer between an anode and a cathode so that holes supplied from the anode and electrons supplied from the cathode are recombined in the organic emission layer to create an exciton being a hole-electron pair, and the exciton is returned to a ground state to generate energy, thereby emitting light.
FIG. 1 is a cross-sectional view of a conventional OLED.
Referring to FIG. 1, a patterned anode 120 is formed on a substrate 110 having a predetermined element.
An organic pixel defining layer 130 for defining a pixel and made of an insulating material for insulation between organic emission layers is formed on the anode 120. The organic pixel defining layer 130 is made of any one material selected from a group consisting of polyimide (PI), polyamide (PA), acryl resin, benzocyclobutene (BCB), and phenol resin.
The organic pixel defining layer 130 may be deposited on the substrate using a spin coating method. The organic pixel defining layer 130 formed by the spin coating method has a thickness of about 1 μm˜2 μm. The organic pixel defining layer 130 is patterned to form an opening, and an organic layer pattern 140 including an organic emission layer is formed on the organic pixel defining layer 130 in addition to the exposed anode.
A cathode 150 is formed on the entire surface of the organic layer pattern 140.
As described above, in the conventional OLED, an organic material as the organic pixel defining layer 130 has been formed by a spin coating method. In this case, since the organic pixel defining layer 130 is formed to a large thickness of about 1 μm˜2 μm, a problem may occur that the organic layer pattern formed by the following process is cut due to a large step of the anode and the organic pixel defining layer 130. Dotted lines designate a portion where the organic layer pattern may be cut. In addition, since the organic pixel defining layer 130 is thick, it is difficult to closely adhere the anode to the organic layer on a donor substrate to thereby require a laser beam having high energy during a transfer process. Therefore, there are problems of degrading transfer efficiency, lowering luminous efficiency of the OLED, and reducing lifetime of the OLED.